Systems and Methods for Calibrating a Conducted Electrical Weapon

ABSTRACT

Systems and methods for calibrating a conducted electrical weapon (“CEW”) to provide a predetermined amount of current for each pulse of the stimulus signal. Providing the predetermined amount of current, close thereto, increases the effectiveness of the stimulus signal in impeding locomotion of a human or animal target. The calibration process enables a CEW to calibrate the amount of charge in a pulse of the stimulus signal in the environmental conditions where the tester operates and also in the field where the environmental conditions may be different from the environmental conditions during calibration.

FIELD OF THE INVENTION

Embodiments of the present invention relate to calibrating a stimulussignal of a conducted electrical weapon (“CEW”) in cooperation with atester.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

Embodiments of the present invention will be described with reference tothe drawing, wherein like designations denote like elements, and:

FIG. 1 is a functional block diagram of a system that creates anenvironment (e.g., ecosystem) for calibrating, transmitting information(e.g., data) related to calibration, and storing information related tocalibration according to various aspects of the present invention;

FIG. 2 is a functional block diagram of an implementation of the CEW ofFIG. 1;

FIG. 3 is a functional block diagram of an implementation of the testerof FIG. 1;

FIG. 4 is a sequence diagram showing messages communicated between theCEW and the tester;

FIG. 5 is a diagram of an implementation of a circuit of the tester ofFIG. 1 for detecting a launch signal;

FIG. 6 is a diagram of another implementation of a circuit of the testerof FIG. 1 for detecting a launch signal;

FIG. 7 is a diagram of an implementation of a circuit of the tester ofFIG. 1 for measuring a pulse of the stimulus signal.

FIG. 8 is a diagram of an implementation of a circuit of the CEW of FIG.1 for providing a pulse of the stimulus signal and measuring a pulse ofthe stimulus signal.

FIGS. 9A and 9B are a flow chart of a method for calibrating a CEWaccording to various aspects of the present invention;

FIG. 10 is a flow chart of a method performed by a CEW, aftercalibration, to generate a reference voltage that relates to acalibrated amount of charge according to various aspects of the presentinvention;

FIG. 11 is a flow chart of a method performed by a CEW, aftercalibration, for adjusting an amount of charge delivered by the pulsesof a stimulus signal for providing a calibrated charge per pulse.

DETAILED DESCRIPTION OF INVENTION

A conducted electrical weapon (“CEW”) is a device that provides astimulus signal through a human or animal target. A stimulus signalinhibits locomotion of the target. Locomotion may be inhibited byinterfering with voluntary use of skeletal muscles and/or causing painin the target. A stimulus signal that interferes with skeletal musclescauses the skeletal muscles to lockup (e.g., freeze, tighten, stiffen)so that the target may not voluntarily move.

A stimulus signal may be more effective at causing skeletal muscle tolock up if a minimum amount of charge is provided by the stimulus signalinto target tissue. A stimulus signal may include a series of pulses.Each pulse of the stimulus signal provides an amount of charge throughthe target. The pulses are delivered at a pulse rate. Providing apredetermined amount of charge or about the same as (e.g., close to) apredetermined amount of charge per pulse may improve the effectivenessof the stimulus signal in impeding the locomotion of the target.Providing the predetermined amount of charge, or close thereto, by eachpulse of the stimulus signal may increase the likelihood of locking upthe skeletal muscle of the target to impede locomotion of the target.

A pulse of a stimulus signal may be referred to as a pulse of current.

A CEW may require periodic calibration to increase the likelihood thatthe CEW provides the predetermined amount of charge per pulse. A CEW maycooperate with a tester to calibrate (e.g., measure, adjust,standardize) the amount of charge provided by a pulse of a stimulussignal. A CEW may measure the amount of charge delivered by each pulseof a stimulus signal independent of a tester. A CEW may adjust (e.g.,change, increase, decrease) the charge delivered by one or more pulsesof a stimulus signal.

During calibration, a CEW may produce a single pulse of the stimulussignal. The CEW measures a voltage that represents the amount of charge(e.g., coulombs) provided by the single pulse. The tester receives thesingle pulse of the stimulus signal and measures the amount of chargeprovided by the pulse. The tester may present (e.g., provide) differentloads (e.g., impedance, resistance) to the CEW into which the pulse isdelivered. The tester reports the amount of charge that it measured forthe pulse to the CEW. Because the tester is periodically calibratedusing accurate measurement instruments, the amount of charge as measuredby the tester is used by the CEW to determine whether the circuits ofthe CEW are delivering a predetermined amount of charge with each pulse.A CEW may receive a message from the tester regarding the amount ofcharge measured by the tester for a pulse of the stimulus signal todetermine whether its circuits are providing the predetermined amount ofcharge.

A CEW may include a handle and one or more deployment units (e.g.,cartridges). Deployment units removeably insert into the handle. Adeployment unit includes one or more wire-tethered electrodes that arelaunched by a propellant toward a target to provide the stimulus signalthrough the target. A signal generator (e.g., stimulus generator) in thehandle generates the stimulus signal for delivery through the target viathe launched electrodes. The cooperation of a handle and one or moredeployment units is more fully disclosed in U.S. patent application Ser.No. 15/259,913 filed Sep. 8, 2016 and is herein incorporated byreference for all purposes.

A CEW may operate in an ecosystem to communicate with other electronicdevices. For example, ecosystem 100, shown in FIG. 1, may include handle110, tester 120, electronic device 130, dock 140, network 150, andserver 170. Ecosystem 100 enables handle 110 to cooperate with tester120 for calibrating handle 110. The ecosystem enables handle 110 or thepower supply (e.g., battery module, power magazine) of handle 110 tocooperate with dock 140 to transfer data from handle 110 to server 170via dock 140 and network 150. Ecosystem 100 further enables handle 110to communicate with electronic device (e.g., smart phone, tablet,computer) 130. One or more deployment units (not shown) may be coupledto handle 110 while handle 110 interacts with electronic device 130.Preferably, the one or more deployment units are removed from handle 110while handle 110 interacts with tester 120.

Ecosystem 100 enables tester 120 to transfer data to server 170 vianetwork 150. Tester 120 may transfer data that originates with (e.g., isgenerated by) tester 120. Tester 120 may transfer data that it receivesfrom any source including handle 110. Data originated by tester 120includes all measurements made by tester 120, all data recorded whiletester 120 is calibrated or its operation verified, and all informationprovided to tester 120 by an operator. Data that is originated by tester120 may also or exclusive be transferred to server 170 via handle 110,electronic device 130 or dock 140, and network 150.

In an implementation, handle 110 transfers data to a battery pack (notshown) inserted into the handle. The battery pack provides energy tohandle 110 to perform the operations of handle 110. The battery pack haselectronic circuits for receiving data from handle 110. When the batterypack is separated from handle 110, battery pack retains the data that itreceived from handle 110. When the battery pack is coupled to dock 140to recharge the battery, the battery pack transfers the data from handle110 to dock 140. A battery pack may further include a wirelesscommunication circuit for transmitting the data from handle 110 to dock140 when the battery pack is within range of dock 140. The battery packmay transfer the data while being recharged.

A handle cooperates with one or more deployment units to provide astimulus signal through a target. A handle controls, at least in part,the generation of the stimulus signal, launching the electrodes from adeployment unit, communicating with other devices in the ecosystem,receiving instructions from a user, detecting physical quantities (e.g.,charge per pulse), and storing information.

A network enables electronic devices to exchange data (e.g.,information). A network may include nodes. A communication link (e.g.,data link) permits the transfer of information between nodes of thenetwork. A communication link may include a wired or wirelessconnection. A node of a network may include a server. A server mayprovide and/or receive data via other nodes and communication links ofthe network.

An electronic device may send or receives data. An electronic device maybe a node in a network. An electronic device may be stationary orportable. An electronic device may present information on a display ofthe electronic device. An electronic device may receive information froma user via a user interface. An electronic device may performcalculations and/or analyze data. An electronic device may perform acalculation and/or analyze data and provide (e.g., transmit) the resultto another device. An electronic device may communicate with otherdevices via a wired or wireless connection. An electronic device mayinclude a smart phone carried by a user. An electronic device mayinclude a tablet device, a portable computer, and/or a mobile dataterminal in a vehicle. An electronic device may operate as anintermediary between a CEW and a node of the network, such as a server.

A tester cooperates with a handle to calibrate the amount of chargeprovided by a pulse of a stimulus signal as discussed above and herein.

An understanding of how a handle cooperates with a tester to calibratethe charge provided by a pulse of a stimulus signal and how a handlecommunicates with other devices in ecosystem 100 may be explained bydiscussing non-limiting implementations of handle 110 and tester 120.

Handle 200 of FIG. 2 is an implementation of handle 110. Handle 200performs the functions of a handle and/or handle 110 discussed above andherein. Handle 200 includes processing circuit 210, memory 220, highvoltage circuit 230, bay 240, bay 250, communication circuit 260, anduser interface 270. Processing circuit 210 includes timer 212, detector214, current source 216. High voltage circuit 230 includes launchgenerator 232, stimulus generator 234, detector 236. High voltagecircuit 230 may provide electrical signals via conductors L1, P1, N1 tobay 240 and LN, PN, and NN to bay 250. Electrical signals (e.g. L1, P1,N1, LN, PN, NN) may be differential or referenced to a common ground.Detector 236 may include measurement capacitor CMH. User interface 270may include safety 272 and trigger 274. Memory 220 may include logs 222.Processing circuit 210 may communicate with and/or control high voltagecircuit 230, memory 220, bay 240, bay 250, communication circuit 260,and user interface 270 via bus 280. Bus 280 may include any conventionaldata and/or control bus.

A processing circuit includes any circuitry and/or electrical/electronicsubsystem for performing a function. A processing circuit may includecircuitry that performs (e.g., executes) a stored program. A processingcircuit may include a digital signal processor, a microcontroller, amicroprocessor, an application specific integrated circuit, aprogrammable logic device, logic circuitry, state machines, MEMSdevices, signal conditioning circuitry, communication circuitry, aconventional computer (e.g., server), a conventional radio, a networkappliance, data busses, address busses, and/or a combination thereof inany quantity suitable for performing a function and/or executing one ormore stored programs.

A processing circuit may further include conventional passive electronicdevices (e.g., resistors, capacitors, inductors) and/or activeelectronic devices (op amps, comparators, analog-to-digital converters,digital-to-analog converters, current sources, programmable logic). Aprocessing circuit may include conventional data buses, output ports,input ports, timers, memory, and arithmetic units.

A processing circuit may provide and/or receive electrical signalswhether digital and/or analog in form. A processing circuit may provideand/or receive digital information (e.g., data) via a conventional bususing any conventional protocol. A processing circuit may receiveinformation, manipulate the received information, and provide themanipulated information. A processing circuit may store information andretrieve stored information. Information received, stored, and/ormanipulated by the processing circuit may be used to perform a functionand/or to perform a stored program.

A processing circuit may control the operation and/or function of othercircuits and/or components of a system. A processing circuit may receivestatus information regarding the operation of other components, performcalculations with respect to the status information, and providecommands (e.g., instructions) to one or more other components, forexample, for the component to start operation, continue operation, alteroperation, suspend operation, or cease operation. Commands and/or statusmay be communicated between a processing circuit and other circuitsand/or components via any type of bus including any type of conventionaldata/address bus.

A memory stores information. A memory provides previously storedinformation. A memory may provide previously stored informationresponsive to a request for information. A memory may store informationin any conventional format. A memory may store electronic digitalinformation. A memory may store information organized in a datastructure and/or database.

A memory includes any semiconductor, magnetic, optical technology, orany combination thereof for storing information. A memory may receiveinformation from a processing circuit for storage. A processing circuitmay provide a memory a request for previously stored information.Responsive to the request the memory may provide stored information to aprocessing circuit. A memory includes a collection (e.g., group, system)of memories that cooperate to store and/or retrieve information.

A memory includes any digital circuitry for storing program instructionsand/or data. Storage may be organized in any conventional manner (e.g.,program code, buffer, circular buffer, data structure). Memory may beincorporated in and/or accessible by a transmitter, a receiver, atransceiver, a sensor, a controller, and a processing circuit.

A high voltage circuit of a CEW may provide a voltage, in the range of500 to 100,000 volts. The high voltage circuit may be coupled to thewire-tethered electrodes to allow delivery of a high voltage to a humanor animal target. A pulse of a stimulus signal may include an ionizationportion and a lower voltage portion. The magnitude of the voltage of theionization portion is between 50,000 and 100,000 volts. The ionizationvoltage may ionize air in a gap between the electrodes and the target.Ionizing air in a gap establishes a low impedance ionization pathbetween the high voltage circuit and the target for delivering a currentthrough target tissue. A high voltage in the range of about 50,000 voltscan ionize air in a gap of up to about one inch.

After ionization, the ionization path persists (e.g., remain inexistence) as long as a current is provided via the ionization path.After ionization, the high voltage circuit provides a current at a lowervoltage for impeding locomotion of the target by causing pain or musclelock up. This current may be referred to as the muscle voltage. Themagnitude of the voltage of the muscle portion of the stimulus pulse isbetween 500 and 10,000 volts. When the current provided at the lowervoltage ceases or is reduced below a threshold, the stimulus signalends, the ionization path collapses (e.g., ceases to exist), and theelectrode is no longer electrically coupled to the target.

A stimulus generator generates (e.g., provides) the stimulus signal. Asdiscuss herein, a stimulus signal includes a series of pulses ofcurrent. A stimulus generator may generator one pulse of the stimulussignal. After each pulse of the stimulus signal, the stimulus generatormay adjust its circuitry prior to providing a next pulse of the stimulussignal. Adjustments may include charging a capacitance to a voltage,enabling a switch, and disabling a switch. A processing circuit maycontrol in whole or in part the operation of a stimulus generator. Aprocessing circuit may perform all or part of the operations of astimulus generator. A stimulus generator may also be referred to as asignal generator.

A bay is a receptacle (e.g., chamber) in a handle of a CEW that accepts(e.g., receives) a deployment unit (e.g., cartridges). A deployment unitmay be removeably inserted (e.g., positioned, placed) in a bay. A handlemay include one or more bays that receive a respective deployment unit.A deployment unit may contain a filament (e.g. wire, tether), one ormore electrodes, a pyrotechnic (e.g. propulsion) for launching theelectrodes to deliver a current through a target.

For example, a deployment unit (not shown) may be removeably insertedinto bay 240 or bay 250 respectively to launch electrodes toward targetto provide a current from high voltage circuit 230 through the target.Launch generator 232 of high voltage circuit 230 may provide anelectrical signal for launching the electrodes from a deployment unit.Stimulus generator 234 may provide the stimulus signal. Duringcalibration, deployment units are removed from all bays of the handleand bay inserts (e.g., couplers, connectors) from the tester, discussedbelow, are inserted into the bays of the handle. The inserts remain inthe bays during testing.

A communication circuit may transmit and/or receive information (e.g.,data). A communication circuit may transmit and/or receive (e.g.,communicate) information via a wireless link and/or a wired connection.A communication circuit may communicate using wireless (e.g., radio,light, sound, vibrations) and/or wired (e.g., electrical, optical)mediums. A communication circuit may communicate using any wireless(e.g., Bluetooth, Bluetooth low energy, Zigbee, WAP, WiFi, NFC, IrDA)and/or any wired (e.g., USB, RS-232, CAN, Firewire, Ethernet, UART, I2C)communication protocols.

A communication circuit may receive information from a processingcircuit for transmission. A communication circuit may provide receivedinformation to a processing circuit.

A communication circuit in one device (e.g., CEW) may communicate with acommunication circuit in another device (e.g., smart phone).Communications between two devices may permit the two devices tocooperate in performing a function of either device.

A user interface may include one or more controls (e.g., switch, touchscreen, button, trigger, safety switch) that permit a user to interactand/or communicate with a device to control (e.g., influence) theoperation (e.g., functions) of the device.

A user interface may provide information to a user. A user may receivevisual and/or audible information from a user interface. A user mayreceive visual information via devices that visually display information(e.g., LCDs, LEDs, light sources, graphical and/or textual display,display, monitor, touchscreen). A user interface may include acommunication circuit for transmitting information to an electronicdevice for presentation to a user. For example, a user interface maywirelessly transmit information to a smart phone for presentation to auser.

A user interface may include voice to text or voice to instructions to aprocessor so that a user may interact with the user interface audibly.

Tester 300 of FIG. 3 is an implementation of tester 120. Tester 300performs the functions of a tester and/or tester 120 discussed above andherein. Tester 300 may include bay insert 340 and 350, processingcircuit 310, memory 320, calibration interface 330, test circuit 360,and user interface 370. A test circuit may include launch tester 362,and load circuit 364. Load circuit 364 may include measurement capacitorCMT. User interface 370 may include LEDs 372 and display 374. Memory 320may include logs 322. Test circuit 360 may further include a circuit(e.g., bay detector) for detecting which bay of the handle provides apulse of the stimulus signal.

Processing circuit 310, memory 320, and user interface 370 may performthe functions of a processing circuit, a memory, and a user interfacerespectively as discussed above.

A bay insert is a plug (e.g. male fitting) of the tester that may beinserted into a bay (e.g., female receptacle) of a handle. The bayreceives and at least partially contains the plug. A bay insert may beplaced into a bay in place of a deployment unit during calibration. Abay insert may include conductors (e.g., terminals). A bay may includeconductors. Inserting a bay insert into a bay electrically couples theconductors of the bay insert to the conductor of the bay.

For example, bay insert and bay include the conductors labeled L1 (e.g.,launch 1), P1 (e.g., positive stimulus 1), N1 (e.g., negative stimulus1), LN (e.g., launch N), PN (e.g., positive stimulus N), and NN (e.g.,negative stimulus N) respectively. Electrical signals (e.g. L1, P1, N1,LN, PN, NN) may be differential or referenced to a common ground.Inserting a bay insert into a bay electrically couples the signals ofthe bay insert to their matching counterpart (e.g., L1 to L1, P1 to P1,and so forth) in the bay. An insert may further include one or moreconductors that electrically couple the tester to the handle so that thehandle may communicate with the tester.

In an implementation, tester 300 includes bay insert 340 and bay insert350. During testing, bay insert 340 and bay insert 350 are inserted intobay 240 and bay 250 of handle 200 respectively.

A calibration interface enables communication between the tester and auser. Via a calibration interface, a tester may provide informationand/or instructions to a user and a user may provide information and/orinstructions to the tester. The calibration interface enables a user,preferably a trained technician, to calibrate the tester. Calibrating atester enables the tester to accurately measure physical quantities(e.g., charge per pulse, voltage magnitude, charge magnitude, time),provide accurate information for calibrating CEWs, operate reliablyduring calibration, and perform its operations consistently during thetesting of many different CEWs.

A calibration interface may include a display that is viewable by auser, one or more indicators (e.g., LEDs, information on the display),one or more controls (e.g., switches, touchscreen) for a user to provideinformation and/or instructions to the tester during calibration of thetester, and one or more ports (e.g., connectors) for connectinginstruments (e.g., volt meter, digital volt meter, current meter, ohmmeter) to the tester to calibrate the tester.

A test circuit receives signals from a CEW. The signals may includesignals used by a CEW to launch electrodes from a deployment unit andstimulus signals. A stimulus signal may be provided to the tester by theCEW as a single pulse or a series of single pulses under the control ofthe handle. A test circuit in cooperate with a processing circuit maymeasure (e.g., determine, detect) and record (e.g., store)characteristics of a pulse (e.g. pulse width, voltage, current, averagecurrent, and charge) provided by a handle. A test circuit may furthermeasure and record the shape of the pulse (e.g., signal) over time. Atest circuit may further detect and report the bay insert (e.g. bayinsert 340, 350) and the signals (e.g. L1, LN, P1, PN, N1, NN)associated with each bay insert that provided the pulse received by thetest circuit.

A test circuit may include a load circuit. A load circuit may present aload (e.g., impedance, resistance) to a handle. The amount of the loadpresented may be selectable. A selectable load may be presented to ahandle during testing and calibration of the stimulus signal. The loadpresented to the signals used to launch the electrodes may or may not beselectable. A load may also be used to detect a connection to a bay.

In an implementation, shown in FIG. 7, load circuit 364 includesresistors RP125-1, RP125-N, RP175, and RP 200 for receiving the positiveportion of the stimulus pulse provided via bay 240 and 250 and resistorsRN125-1, RN125-N, RN175, and RN200 for receiving the negative portion ofthe stimulus pulse provided via bay 240 and 250. The values of theresistors RP125/RN125, RP175/RN175, and RP200/RN200 are 120 ohms, 175ohms and 200 ohms respectively. Switches 720 and 722 are controlled byprocessing circuit 210 at the request for handle 200 to set theimpedance seen by the handle 200 to 250 ohms, 600 ohms, or 1000 ohms.

A load circuit may further include a measurement capacitor. Ameasurement capacitor may receive and store an electric charge. Thevoltage across the measurement capacitor is proportional to the amountof charge stored on the capacitor. A processing circuit may measure thevoltage across the capacitor. A processing circuit may determine (e.g.,compute, calculate) the charge stored on the measurement capacitor.

In an implementation, load circuit 364 includes measurement capacitorCMT shown in FIG. 7. The charge stored on measurement capacitor CMTafter test circuit 360 receives a pulse of the stimulus signal fromhandle 200 represents the amount of charge provided by the pulse.Processing circuit 310 may measure the voltage across measurementcapacitor CMT at terminal 740. Processing circuit 310 may use thevoltage measured across measurement capacitor CMT to calculate thecharge provided by the pulse and stored on measurement capacitor CMT.The amount of charge provided by the pulse, as measured acrossmeasurement capacitor CMT, may be reported to handle 200.

Prior to receiving a next pulse from handle 200, processing circuit 310may close switch 730 to discharge measurement capacitor CMT. Dischargingmeasurement capacitor CMT removes the charge stored on measurementcapacitor CMT from a previous pulse and prepares measurement capacitorCMT to store the charge from a next pulse of the stimulus signal.

In an implementation, load circuit 364 includes resistor R10 as shown inFIG. 7. The waveform shape (e.g., rise time, fall time, pulse duration,pulse magnitude) of a pulse may be captured by processing circuit 310across resistor R10. Processing circuit 310 may measure the voltageacross R10 at terminal 742. Processing circuit 310 may use the voltagemeasured across R10 to calculate the charge provided by the pulse. Theinformation (e.g., characteristics) measured by tester 300 with respectto a pulse of the stimulus signal may be reported to handle 200.Resistor R10 may operate as a voltage divider in load circuit 364. In animplementation, resistor R10 is 10 ohms.

Test circuit 360 also includes launch tester 362 for receiving thesignals provided by a handle 200 for launching electrodes from adeployment unit. Launch tester 362 may identify whether a launch signalwas provided by bay 240 (e.g., L1) or bay 250 (e.g., LN). In animplementation of launch tester 362, launch tester 510 in FIG. 5includes gaps of air GP1 and GPN. The length of gaps GP1 and GPN may beset so that a launch signal has a minimum voltage threshold to be ableto ionize air in gaps GP1 and GPN. The light from the ionization (e.g.,arc) coincident with ionization causes current to flow in phototransistors 530 and 532 respectively thereby indicating that the launchsignals were received. The flow of current in photo transistors 530 and532 may be detected by processing circuit 310 via a change in thevoltage at nodes 520 and 522.

In another implementation of launch tester 362, launch tester 610 ofFIG. 6 includes light emitting diodes LED1 and LEDN. The diodes may beselected so that a launch signal has a minimum voltage threshold tocause the LEDs to emit light. The light from LED1 and LEDN causescurrent to flow in photo transistors 630 and 632 respectively therebyindicating that the launch signals were received. The flow of current inphoto transistors 630 and 632 may be detected by processing circuit 310via a change in the voltage at nodes 620 and 622.

The functions of a user interface are discussed above. In animplementation of tester 300, user interface 370 includes light emittingdiodes (e.g., LEDs) 372 and display 374.

A display may be used to present information to the user. Informationmay include text and/or video information. Visual information presentedby a display may further include audio information that relates toand/or explains the video information. A display may include touchscreen technology for providing a display of information and forreceiving input (e.g., instructions) from a user. A touch screen displaymay present one or more controls (e.g., icons) for manual selection by auser.

During the process of calibrating a handle, the handle and the testercommunicate with each other. Through the communications, the handlecontrols the tests that are performed by the tester. The handle requestsand receives test results from the tester. The information communicatedbetween the handle and the tester may be accomplished in any suitablemanner. Communication may include sending and/or receiving digital dataand/or analog signals.

An implementation, the process of communication to perform calibrationthat occurs between handle 200 and tester 300 includes request 402,ready 404, send signal 406, request results 408, send result 410, andend test 412.

In request 402, handle 200 sends a test request to tester 300. A testrequest may include parameters to specify test set up such as bay numberto be tested, load impedance, and test type (e.g., stimulus, launch).Because a test is not performed until a test request is formed andprovided by handle 200 to tester 300, handle 200 controls which testsare performed.

In ready 404, tester 300 sends a ready signal to handle 200. Aftertester 300 receives a test request, processing circuit 310 of tester 300initializes the tester and sets the circuits of test circuit 360 toperform the test requested. When tester 300 is ready to receive thesignal from handle 200, tester 300 sends a ready signal to handle 200.

In send signal 406, handle 200 sends a test signal (e.g. launch signal,stimulus signal) to tester 300. Tester 300 detects the signal sent byhandle 200 and measures (e.g. voltage, charge, bay) the stimulus.Processing circuit 310 records the results of the test measurements(e.g., indicia of the test measurements). In send signal 406, handle 200not only sends the stimulus pulse to tester 300, but handle 200 alsomeasures characteristics of the pulse independent of tester 300.

In request result 408, handle 200 sends a results request to tester 300.Tester 300 receives a results requests, processing circuit 310 preparesa message that reports results of test measurements.

In send result 410, tester 300 sends a message to handle 200 thatcontains the results of a test (e.g., amount of charge delivered by apulse of the stimulus signal, detection of launch signal). Handle 200receives the test results from tester 300. The processing circuit 210 ofhandle 200 may store test results in memory 220. Handle 200 may transfertest results to a server 170 via a network 150.

In test end 412, handle 200 sends a message to tester 300 that testsession is ended.

Processes request 402, ready 404, send signal 406, request results 408and send result 410 may be repeatedly performed, under the control ofhandle 200, until calibration is accomplished.

Handle 200 repeatedly sends test request 402 to tester 300 for the sameor different tests and requests the test results for each test untilhandle 200 has sufficient information to calibrate its operation towithin the specified ranges of operation. When tester 200 has theinformation it needs to adjust its own operation, tester 200 sends testend 412 message to tester 300 to terminate the test.

If after repeated tests, tester 200 cannot bring its operation into therange of desired performance, tester 200 provides a notice of thefailure to the user, tester 300, and/or the agency of the user and sendstest end 412 message to terminate the test.

Circuit 800 of FIG. 8 is an implementation of a high voltage circuit ofhandle 200 that provides the stimulus pulse. Circuit 800 includes astimulus generator 234 and a detector 236. The stimulus generator 234includes capacitors CI, CMP, CMN, transformers T710, T712, T714, T716,and switches S720, S722, S724, S726. The detector 236 includesmeasurement capacitor CMH and switch S728. Capacitors CI, CMP, and CMNare part of the stimulus generator and are charged to provide a stimuluspulse. The polarity of the charge on capacitor CMP is the opposite ofthe polarity of the charge on CMN. In this example, we will suppose thatvoltage across capacitors CI and CMP is positive with respect to groundwhile the voltage across capacitor CMN is negative.

After the capacitors are charged, processing circuit 210 of handle 200selects one positive electrode and one negative electrode. The positiveelectrodes (e.g. electrode P1, electrode PN) are those electrodes thatare coupled to capacitor CMP through the secondary winding oftransformers T710 and T712 and the negative electrodes (e.g. electrodeN1, electrode NN) are those electrodes that are coupled to capacitor CMNthrough the secondary winding of transformers T714 and T716. Whenprocessing circuit 210 closes the switches (e.g., SCR) on one negativeand one positive electrode, for example electrode P1 and electrode N1,the current from capacitor CI discharges into the primary winding of thetransformer coupled to the selected electrodes. In this example, switchS720 and switch S724 are closed so that the charge from capacitor CIdischarges into the primary winding of transformers T710 and T714. Thecurrent in the primary winding induces a current at a higher voltage(e.g., 50,000 volts) in the secondary winding which causes ionization ina gap of air between the selected electrodes and the target as discussedabove. Most of the charge on capacitor CI is spent (e.g., used) ionizingair in the gap. Once the ionization path is established, the charge fromcapacitors CMP and CMN discharges through the target via the ionizationpath. The discharge of capacitors CI, CMP, and CMN produces a pulse of astimulus signal.

Measurement capacitor CMH may be used to measure the charge (via voltageVMH) sent to the electrodes into the target or into the load circuit ofthe tester. The voltage VMH across measurement capacitor CMH may bemeasured at terminal 802 by processing circuit 210. The charge stored onmeasurement capacitor CMH after the discharge of capacitors CI, CMP, andCMN represents the amount of charge provided by the pulse of thestimulus signal. Processing circuit 210 may use the voltage measuredacross measurement capacitor CMH to calculate the charge provided by thepulse and stored on measurement capacitor CMH.

Prior to sending a next pulse, processing circuit 210 may close switchS728 to discharge measurement capacitor CMH. Discharging measurementcapacitor CMH removes the charge stored on measurement capacitor CMHfrom a previous pulse and prepares measurement capacitor CMH to storethe charge from a next pulse of the stimulus signal.

In the case of measuring the charge provided by a pulse of the stimulussignal, send result 410 sends the amount of charge measured by tester300 to handle 200. Because handle 200 independently measured the amountof charge (via voltage VMH) provided by the same pulse of the stimulussignal, as discussed above, handle 200 is in a position to record thevoltage VMH across measurement capacitor CMH that represents thepredetermined amount of charge as reported by tester 300. The comparisonof the independently measured charge enables handle 200 to adjust itscircuits and its operations so that each pulse of a stimulus signal hasthe highest likelihood of providing a predetermined amount of charge.Providing a predetermine amount of charge with each pulse of the currentincreases the likelihood of interfering with locomotion of a target bylocking up the muscles of the target.

In an implementation, the predetermined amount of charge is 63microcoulombs per pulse. Preferably, each pulse of the stimulus signalprovides the predetermined amount of charge per pulse. Factors thatdetermine the predetermined amount of charge for impeding locomotion ofa target include the number of pulse provided in a stimulus signal, thepulse rate, the pulse width, the pulse profile (e.g., shape), and timebetween pulses. The predetermined amount of charge may, taking the otherfactors of the stimulus signal into account, may fall in a range of 40microcoulombs per pulse to 100 microcoulombs per pulse.

A pulse of a stimulus signal provides about the same amount of charge(e.g., close to) as the predetermined amount of charge when the pulse ofthe stimulus signal provides an amount of charge that is thepredetermined amount of charge pulse or minus five percent (5%) of thepredetermined amount of charge. For an implementation in which thepredetermined amount of charge is 63 microcoulombs, a pulse of thestimulus signal provides about the same amount of charge as thepredetermined amount of charge when the pulse provides between 63microcoulombs minus five percent (e.g., 3.15 microcoulombs), which is59.85 microcoulombs and 63 microcoulombs plus five percent (e.g., 3.15microcoulombs), which is 66.15 microcoulombs. For an implementation inwhich the predetermined amount of charge is 100 microcoulombs, a pulseof the stimulus signal provides about the same amount of charge as thepredetermined amount of charge when the pulse provides between 100microcoulombs minus five percent (e.g., 5 microcoulombs), which is 95microcoulombs and 100 microcoulombs plus five percent (e.g., 5microcoulombs), which is 105 microcoulombs.

Methods 900, 1000, and 1100 are performed by a handle and/or a tester tocalibrate a handle. Method 900 is performed by the cooperation of ahandle, for example handle 200, and a tester, such as tester 300.Process 1000 is performed by a handle, such as handle 200, aftercalibration of the handle and during initialization just after armingthe handle for use. Method 1100 is performed by a handle, such as handle200, while the handle is providing a stimulus signal. Each method isdiscussed below.

Method 900 is performed by a handle. It includes processes short 904,charge 906, charge 908, remove 910, pulse 912, measure 914, report 916,compare 918, record 920, increase 922, decrease 924, compare 926,discharge 928, start time 930, charge 932, end time 934, set 936, store938, exit 940.

When handle 200 provides a pulse of the stimulus signal via the selectedelectrodes a path for current flow is established. The path is from thepositive stimulus capacitor (CMP) through the positive electrode (e.g.P1, PN), the load circuit 364 of tester 300, the negative electrode(e.g. N1, NN), the negative stimulus capacitor (CMN), and themeasurement capacitor (CMH) of handle 200. At the beginning of thepulse, the voltage (VMH) on measurement capacitor CMH begins at a valueof zero volts. The charge is removed from measurement capacitor CMH byclosing switch S728 at the start of charging the stimulus capacitors CMPand CMN. When closed, switch S728 shorts measurement capacitor CMH. Oncethe stimulus capacitors are charged and it is time to release a pulse ofthe current, switch S728 is opened and the current of the pulse flowsthrough all of the components of the above path.

As the current flows through the path, the charge the stimuluscapacitors CMP and CMN is transferred to the measurement capacitor CMH.As the pulse of the stimulus signal ends, the amount of charge deliveredby the pulse of the stimulus signal is stored on measurement capacitorCMH. The voltage (VMH) on handle measurement capacitor CMH relates tothe amount of charge delivered by the pulse of the stimulus signal. Theamount of charge reported by the tester 300 is the amount of chargecollected by measurement capacitor CMH, so the voltage VMH acrossmeasurement capacitor CMH relates to the amount of charge reported bytester 300.

When tester 300 reports that the pulse of the stimulus signal deliveredthe predetermined amount of current, handle 200 knows that the amount ofcharge delivered by the pulse is the predetermined amount of charge.Handle 200 then knows that the amount of charge on measurement capacitorCMH and the voltage VMH across measurement capacitor CMH represents thepredetermined charge for the current environmental conditions. Handle200 records the voltage across measurement capacitor CMH as the goldenvoltage of handle 200 (e.g., golden voltage, Vgolden) for the currentenvironmental conditions. Under the environmental conditions, handle 200knows that each time it measures Vgolden across measurement capacitorCMH that handle 200 has delivered the predetermined amount of charge inthe pulse.

In process discharge 904, the handle initializes measurement capacitorCMH to measure the amount of charge provided by a pulse of the current.Measurement capacitor CMH is initialized by removing the charge storedon measurement capacitor CMH. For example, processing circuit 210 closesswitch S728 to discharge measurement capacitor CMH. Dischargingmeasurement capacitor CMH removes the charge stored on measurementcapacitor CMH from a previous pulse and prepares measurement capacitorCMH to store the charge from a next pulse of the stimulus signal. Forexample, processing circuit 210 discharges measurement capacitor CMH byclosing switch S728 so that measurement capacitor CMH is grounded,thereby removing all charge stored by measurement capacitor CMH.

In process charge 906, the handle 200 charges capacitors CMP and CMN toa voltage so that capacitors CMP and CMN will provide a target amount ofcharge. The target amount of charge is the predetermined amount ofcharge discussed above to provide a more effective stimulus signal.Processing circuit 210 may set target voltages (e.g., VMPT, VMNT),discussed in more detail below, to which capacitors CMP and CMNrespectively are charge prior to providing a pulse of the stimulussignal. Target voltages VMPT and VMNT are adjusted as discussed below tochange the amount of charge provided by a pulse of the stimulus signalwith the goal of providing the predetermined amount of current or anamount close thereto. On a first iteration of process charge 904, thetarget voltages VMPT and VMNT for charging capacitors CMP and CMNrespectively (e.g., VMPT across capacitor CMP, VMNT across capacitorCMN) may be set by estimating the target voltages based on stored data,by using empirical data to determine preliminary values, or to defaultvalues stored by handle 200. Processing circuit 210 controls thecharging of capacitors CI, CMP and CMN. Processing circuit 210 maintainsin memory the values of the target voltages VMPT and VMNT and controlsthe charging process so that capacitors CMP and CMN are charged to thetarget voltages.

In process charge 908, the handle charges ionization capacitor CI to atarget voltage. As discussed above, capacitor CI provides the ionizationportion of the current pulse. For example, processing circuit 210 ofhandle 200 controls the charging of capacitor CI.

In process remove 910, the handle removes the short from measurementcapacitor CMH. This is timed to happen just before a pulse of thestimulus signal is sent. Measurement capacitor CMH is initialized tostart collecting charge delivered by the pulse of the stimulus signal.For example, processing circuit 210 opens switch S728 to allowmeasurement capacitor CMH to collect charge from a pulse of the stimulussignal.

In process pulse 912, the handle 200 may send a pulse of the stimulussignal to tester 300. The pulse of current is a pulse of a stimulussignal as discussed above. For example, processing circuit 210 mayselect the signals (e.g., P1, N1, PN, NN) of bay 240 and/or bay 250 thatprovide the pulse to the signals (e.g., P1, N1, PN, NN) of bay inserts340 and 350. Pulse generation is discussed above.

After handle 200 provides the pulse of the stimulus signal to tester300, process measurement 914 measures the voltage VMH on measurementcapacitor CMH at terminal 802. For example, processor 210 measures thevoltage across measurement capacitor CMH.

In process report 916, handle 200 receive a message from tester 300. Theinformation provided in the message includes the amount of chargemeasured by tester 300 for the pulse that was received and for whichhandle 200 has measured the voltage across measurement capacitor CMH.Tester 300 determines the amount of charge provided by a pulse bymeasuring the voltage across capacitor CMT and calculating the amount ofcharge on the capacitor. As discussed above, the amount of charge oncapacitor CMT after the current pulse has been received represents theamount of charge delivered by the current pulse.

Handle 200 uses the reported amount of charge for the pulse to thevoltage measured across measurement capacitor CMH. The amount of chargereported by tester 300 informs handle 200 that in the environment inwhich the test is being performed, the voltage measured acrossmeasurement capacitor CMH means that handle provided a specific amountof charge.

The term environment includes the physical characteristics of handle 200and its ambience. Physical characteristics of the ambience of anenvironment include any conventional physical property that occurs in anarea including ambient temperature, humidity, presence of direct sunlight, presence of moisture (e.g., rain), and particulates (e.g., smoke,fog). Physical characteristics of a handle include any conventionalphysical property of a handle including operating temperature of thehandle, age of the components of the handle, and presence of moisture(e.g., condensate).

For example, if handle 200 measures voltage V1 across measurementcapacitor CMH and tester 300 reports 60 microcoulombs, handle 200 knowsthat each time it measures voltage V1 across measurement capacitor CMH,it has provided a pulse that delivered 60 microcoulombs. If handle 200measures voltage V2 across measurement capacitor CMH and tester 300reports 65 microcoulombs, handle 200 knows that each time it measuresvoltage V2 across measurement capacitor CMH, it has provided a pulsethat delivered 65 microcoulombs or about 65 microcoulombs. Handle 200can use the information that relates the voltage across measurementcapacitor CMH to an amount of charge to adjust its own circuits toprovide the predetermined (e.g., target) amount of charge. For example,handle 200 can adjust, either increase or decrease, the voltage oncapacitors CMP and CMN primarily and CI secondarily to increase ordecrease the amount of charge provided in a pulse of the stimulussignal. By adjusting the amount of charge on the capacitors (e.g., CI,CMP, CMN) of the high voltage circuit (e.g., circuit 800), handle 200can use the information provided by tester 300 to determine the circuitsettings that deliver the predetermined amount of charge.

The handle may use measurements (e.g. voltage across CMH) from severalpulses and use corresponding reports for each pulse from the tester toaverage test data (e.g. simple moving average, weighted moving average)to determine the amount of charge delivered by any one pulse.

The relationship between the voltage across measurement capacitor CMHand the reported amount of charge applies only in the environmentalconditions (e.g., temperature, humidity) of the calibration environmentat the time the measurements are performed. In a different environment,as discussed below, the relationship between the voltage acrossmeasurement capacitor CMH and the amount of charge provided by a pulseof the stimulus signal may be different. The physical characteristics ofthe environments may be different.

In process comparison 918, the amount of charge (e.g., QMT) reported bytester 300 to handle 200 in process report 916 is compared to the amountof charge that has been predetermined to improve the effectiveness ofthe stimulus signal. As discussed above, providing the predeterminedamount of charge or about the same as a predetermined amount of chargeper pulse may improve the effectiveness of the stimulus signal therebyresulting in skeletal muscle lockup. If the amount of charge deliveredby the pulse provided in process 912 is about the same as thepredetermined amount of charge, handle 200 may perform further processes(processes 920 and 928-938, method 1000, method 1100) so that handle 200can deliver pulses of current that provide the predetermined amount ofcharge, or close thereto, in an environment that is different from thecalibration environment. If the amount of charge delivered by the pulseis the same or about the same as the predetermined amount of charge,execution moves to process record 920.

If the amount of charge delivered by the pulse provided in process 912is not the same or about the same as the predetermined amount of charge,execution moves to process compare 926 and following processes (e.g.,922-924) so that handle 200 may adjust the charge delivered by a nextpulse of the stimulus signal so that it may be closer to thepredetermined amount of charge.

In process comparison 926, the amount of charge reported by tester 300is compared to the predetermined charge to determine whether thereported amount of charge is greater than the predetermined amount ofcharge. If the amount of reported charge is greater than thepredetermined charge, handle 200 determines that it should decrease theamount of charge delivered by a next pulse of the stimulus signal andexecution moves to process decrease 924. If the amount of reportedcharge is not greater than the predetermined charge, handle 200determines that it should increase the amount of charge delivered by thenext pulse of the stimulus signal and execution moves to processdecrease 924. As discussed above, handle 200 adjusts the amount ofcharge delivered by a pulse by adjusting the amount of charge stored oncapacitors CMP and CMN prior to delivering the pulse.

In process increase 922, handle 200 increases the amount of chargestored on capacitors CMP and CMN prior to delivering a next pulse of thestimulus signal. The amount stored on capacitors CMP and CMN isincreased by charging the capacitors to a higher voltage prior todelivering the pulse. Processing circuit 210 may maintain a record ofthe voltages to which capacitors CMP and CMN are charged for each pulseprovided. Processing circuit 210 may use the record of voltages and theinformation regarding the amount of charge provided by each pulse todetermine a target voltage, VMPT and VMNT, for capacitors CMP and CMNrespectively. Processing circuit 210 may adjust the target voltage up ordown, in the case of process increase 922 the adjustment is up, toadjust the voltage to which capacitors CMP and CMN are charged andthereby the amount of charge delivered by a pulse.

Adjusting the target voltages VMPT and VMNT up increases the voltage towhich processing circuit 210 charges capacitors CMP and CMN prior toproviding a pulse of the stimulus signal. Charging a capacitor to ahigher voltage increases the amount of charge stored on the capacitor.Processing circuit 210 may have knowledge of the values (e.g.,capacities) of capacitors CMP and CMN and may even calculate the amountof charge stored on capacitors CMP and CMN; however, handle 200 relieson tester 300 to accurately measure and report the amount of chargedelivered by a pulse, so processing circuit 210 does not have a need tocalculate the amount of charge stored on capacitors CMP and CMN.However, processing circuit 210 may calculate the amount of charge oncapacitors CMP and CMN or the increase in the amount of charge oncapacitors CMP and CMN if it is needed or desirable for determining newvalues for target voltages VMPT and VMNT.

Process decrease 924 performs the inverse process of process increase922. In process decrease 924, handle 200 decreases the amount of chargestored on capacitors CMP and CMN prior to providing a pulse. As discussabove, processing circuit 210 may use stored information to adjusttarget voltages VMPT and VMNT downward so that the next pulse of thestimulus signal provides less charge that is possibly closer to thepredetermined amount of charge. Processing circuit may perform the sametypes of operations as discussed with respect to process increase 922,but in a way to decrease the amount of charge delivered by the nextpulse of the stimulus signal.

Processes 904-918 and 922-926 are repeated until process 918 determinesthat the amount of charge delivered by the pulse of the stimulus signalis about the same as the predetermined (e.g., target) amount of charge.Once handle 200 has adjusted (e.g., set) its operation so that thepredetermined amount of charge is delivered, execution moves to processrecord 920.

In process record 920, processing circuit 210 records (e.g., stores) thevalue of voltage VMH, measured across measurement capacitor CMH in themost recent execution of process measure 914. This measured value of VMHis referred to as the golden voltage of handle 200 (e.g., goldenvoltage, Vgolden) because it is the voltage across measurement capacitorCMH just after delivery of a pulse of the stimulus signal that providedthe predetermine amount of current or an amount close thereto. In theenvironment in which the calibration is being conducted (e.g.,calibration environment), each time the voltage across measurementcapacitor CMH is the golden voltage, or close thereto, the amount ofcharge delivered by the pulse of the stimulus signal was thepredetermined amount of charge or close thereto. In other words, handle200 now has the information that it needs to adjust its circuits toprovide the predetermined amount of charge for the environment in whichit is presently operating (e.g., operating environment).

Process record 920 may also record voltages VMPT and VMNT. Voltages VMPTand VMNT may be recalled from memory and capacitors CMP and CMN chargedto VMPT and VMNT respectively.

If handle 200 were to remain in the environment prevalent duringcalibration (e.g., cooperating with tester 300), each time handle 200measured Vgolden across measurement capacitor CMH, it would know thatthe pulse that was just delivered provided the predetermined amount ofcharge. However, handle 200 will be used in environmental conditionsthat differ from the calibration environment. Further, the components ofhandle 200 change with time thereby changing the voltage measured acrossmeasurement capacitor CMH over time. In different environmentalconditions, for example a different temperature, measuring Vgoldenacross measurement capacitor CMH may not mean that the predeterminedamount of charge was delivered by the pulse because the capacitance ofmeasurement capacitor CMH changes with temperature. As environmentalconditions change or the age of the components, the voltage acrossmeasurement capacitor CMH will change when the predetermined amount ofcharge is delivered.

Equation no. 1 below highlights the issue of the change in environmentalconditions. In equation no. 1 below, the amount of charge Q is equal tothe capacitance of measurement capacitor CMH multiplied by the voltagemeasured across measurement capacitor CMH.

Q=C*V.  Equation no. 1

It is desirable to determine the voltage across measurement capacitorCMH in different environmental conditions while measurement capacitorCMH holds the predetermined amount of charge so that in differentenvironmental conditions handle 200 may determine whether a pulseprovided the predetermined amount of charge.

Fortunately, the amount of charge provided to a capacitor may bedetermined in another way that is independent of capacitance. Inequation no. 2 below, the amount of charge Q is equal to the magnitudeof the current multiplied by the duration of time of the current.

Q=I*t  Equation no. 2

Processing circuit 210 of handle 200 may include a current source and atimer. A current source may provide current such that the chargeprovided per unit time is fairly constant regardless of the environmentin which the current source operates. A current source that providescharge per time that varies little over temperature and/or operatingvoltage may be referred to as a constant current source or a temperatureinsensitive (e.g., independent) current source. In an implementation,the current provided by a current source over the operating temperatureand voltage of the current source may vary plus or minus three percent(3%). Providing a current that varies plus or minus three percent over arange of temperature and/or voltage may be considered to besubstantially constant.

A timer may measure an elapse of time. A time may start counting, countfor a duration of time, then stop counting. The count of the timerrepresents the time that elapsed while the timer was counting. Thelength of the elapse of time is the duration of the elapse or theduration of time during which the counter was counting. A duration oftime is a period of time.

The variation of the current source and the operation of the timer overtemperature may be fairly minimal, so that processing circuit may chargea capacitance with the predetermined amount of charge in anyenvironmental conditions. Once a capacitance, in particular measurementcapacitor CMH has been charged with the predetermined amount of charge,the voltage across measurement capacitor CMH represents the targetvoltage for providing the predetermined amount of charge in a pulse.

To determine the target voltage across measurement capacitor CMH toprovide the predetermined amount of charge in any environmentalcondition, handle 200, while it is in the environmental conditions oftester 300, uses its current source to convert Vgolden to a golden time(Tgolden). If a known amount of current is provided for a Tgolden amountof time, the amount of charge provided is the predetermined amount ofcharge regardless of environmental conditions.

To determine Tgolden, processing circuit 210 uses its current source tocharge measurement capacitor CMH to Vgolden while measuring the chargingtime, which is Tgolden, using a timer. Since Vgolden represents apredetermined amount of charge while handle 200 is in the calibrationenvironment, Tgolden represents the amount of time it takes to put thepredetermined amount of charge on measurement capacitor CMH using thecurrent source. Because the amount of current provided by the currentsource changes little over temperature and the accuracy of the timeralso changes little over temperature, Tgolden represents the amount oftime it takes for the current source to charge measurement capacitor CMHwith the predetermined amount of charge over all environmentalconditions.

While handle 200 is still in the calibration environment (e.g.,proximate to tester 300) handle 200 may perform additional processes(e.g., 928-938) to determine Tgolden so that voltage across measurementcapacitor CMH when it holds the predetermined amount of charge in allenvironmental conditions may be determined.

In process discharge 928, handle 200 initializes the voltage acrossmeasurement capacitor CMH to a known value by shorting measurementcapacitor CMH to ground. Shorting measurement capacitor CMH to groundremoves all charge from measurement capacitor CMH. Process discharge 928performs the same operations and achieves the same result as processdischarge 908. Execution proceeds to process start time 930.

In process start time 930, handle 200 initializes a timer and preparesthe timer to measure a period of time. For example, processing circuit210 includes a microprocessor that initializes one of its timers to zeroand instructs the timer to start counting up. The count of the timerincrements in accordance with a clock (e.g., crystal, oscillator). Withmany crystals, the frequency of the crystal varies little (e.g., 0.50ppm) over the temperature range of operation of the crystal, so that aperiod of time counted by a timer varies little over temperature.Execution proceeds to process charge 932.

In charge 932, a current source of processing circuit 210 provides acurrent to charge measurement capacitor CMH while processing circuit 210monitoring the voltage across VMH. The timer initialized above startscounting at about the same time that the current source starts providingits current to measurement capacitor CMH. When processing circuit 210detects that the voltage across measurement capacitor CMH is equal toVgolden control moves to process end time 934.

In process end time 934 and process set 936, processing circuit 210stops the count of the timer started in process time 930 and records thevalue of the timer in non-volatile memory as the golden time of handle200 (Tgolden). The golden time represents the duration of time that thecurrent source provides a current to charge measurement capacitor CMH tothe golden voltage. Storing Tgolden allows the processing circuit 210 tolater to calibrate the stimulus signal by determining the voltage acrossmeasurement capacitor CMH that represents providing the predeterminedamount of charge or close thereto for the operating environmentalconditions. Storing Tgolden for later retrieval permits a handle tocalibrate the amount of charge provided by a pulse of the current in thecalibration environment and in any other environmental conditionwherever the handle is operating. Storing Tgolden enables a handle tocalibrate the stimulus signal in environments that differ from thecalibration environment.

In process exit 938, the handle determines calibration is complete andthe handle exits the calibration mode.

Handle 200 performs method 1000 self-calibrate while in use in the fieldin the current environmental conditions. Handle 200 may perform method1000 each time the handle is activated for use (e.g., armed). Method1000 includes processes arm 1002, retrieve 1004, charge 1006, set 1008,end 1010.

In process arm 1002, the user of the CEW manipulates (e.g., switches,moves) the safety switch on the CEW to the armed position. Arming handle200 causes processing circuit 210 to perform method 1000 toself-calibration handle 200. Processing moves to process 1004.

In process retrieve 1004, the processing circuit 210 retrieves fromnonvolatile memory Tgolden. Processing moves to process 1006.

In process discharge 1006, handle 200 initializes the voltage acrossmeasurement capacitor CMH to a known value by shorting measurementcapacitor CMH to ground. Shorting measurement capacitor CMH to groundremoves all charge from measurement capacitor CMH. Process discharge1006 performs the same operations and achieves the same result asprocess discharge 908 and 928. Execution proceeds to process charge1008.

In process charge 1008, the processing circuit 210 uses a current sourceto charge measurement capacitor (CMH) for the duration of time specifiedby Tgolden as counted by a timer of processing circuit 210. Processingcircuit 210 starts the timer and providing the current at about the sametime. Providing the constant current to measurement capacitor CMH forthe duration Tgolden charges measurement capacitor CMH with thepredetermined amount of charge. The voltage across measurement capacitorCMH after being charged with the predetermined amount of charge is thevoltage that will be on measurement capacitor CMH each time a pulseprovides the predetermined amount of charge for the currentenvironmental conditions. This voltage is referred to as the operationaltarget voltage. Processing moves to process 1010.

In process set 1010, processing circuit 210 measures the voltage acrossmeasurement capacitor CMH and stores the value as the operational targetvoltage. Processing circuit 210 compares the voltage across measurementcapacitor CMH after delivery of each pulse and compares the voltage tothe operational target voltage to determine whether the pulse deliveredthe predetermined amount of charge. Processing circuit 210 uses theresult of the comparison to adjust its operation so that the chargedelivered by each pulse is as about the same as the predetermined amountof charge as possible. The processes performed to adjust operation ofhandle 200 is discussed below with respect to method 1100.

In process end 1012, the processing circuit 210 finishes itsself-recalibration.

After handle 200 has completed self-calibration method 1000, handle 200may deliver a stimulus signal. A stimulus signal includes a series ofcurrent pulses. Handle 200 performs method 1100, each time the triggeris pulled, to attempt to deliver the predetermined amount of charge witheach pulse of the stimulus signal.

Method 1100 includes processes pull trigger 1102, discharge 1104, charge1106, remove 1108, pulse 1110, measure 1112, decision 1114, compare1116, increase 1118, decrease 1120, compare 1122, and end 1124.

In process pull 1102, the user of the CEW has pulled the trigger tolaunch the electrodes from a deployment unit (e.g., cartridge) toward atarget to deliver the stimulus signal through the target. The CEWprepares itself to provide the pulses of the stimulus signal. Forexample, processing circuit 210 may detect the pull of trigger 274.Processing circuit 210 may perform the processes of method 1100, inwhole or part, or control other components, such as stimulus generator234, launch generator 232, and detector 236 to perform method 1100.Execution moves to process discharge 1104.

In process discharge 1104, the handle initializes measurement capacitorCMH to measure the amount of charge provided by a pulse of the current.Measurement capacitor CMH is initialized by removing the charge storedon measurement capacitor CMH (e.g., initializing to zero). For example,processing circuit 210 closes switch S728 to discharge measurementcapacitor CMH. Discharging measurement capacitor CMH removes the chargestored on measurement capacitor CMH from a previous pulse and preparesmeasurement capacitor CMH to store the charge from a next pulse of thestimulus signal. Processing circuit 210 discharges measurement capacitorCMH by closing switch S728 ground capacitor CMH to remove all chargestored on measurement capacitor CMH. Execution moves to process charge1106.

In process charge 1106, the CEW charges stimulus capacitors CMP and CMNto a target voltage VMPT and VMNT respectively in preparation ofproviding a pulse charge through a target. The amount of charge storedon CMP and CMN may be adjusted for each pulse to deliver thepredetermined amount of charge to the target. The initial values of VMPTand VMNT may be set by estimating the target voltages based on storeddata, by using empirical data to determine initial values, or by usingdefault values stored by handle 200. Execution moves to process remove1108.

In process remove 1108, the handle removes (e.g., opens) the shortacross measurement capacitor CMH. Removing the short across CMH is timedto happen just before a pulse of the stimulus signal is provided bystimulus generator 234 to selected cartridge. Measurement capacitor CMHis initialized so that it may collect the charge provided by the nextpulse of the current. For example, processing circuit 210 opens switchS728 to allow measurement capacitor CMH to collect charge from a pulseof the stimulus signal that is about to be delivered by capacitors CMPand CMN in process 1110. Execution moves to process pulse 1110.

In process pulse 1110, handle 200 provides a current pulse to theelectrodes that have been selected to provide the pulse of the stimulussignal. For example, the processing circuit 210 selects signal P1 andsignal N1 of bay 240 to provide the pulse of the stimulus signal toelectrodes P1 and N1. Processing circuit 210 closes switch S720 and S724which causes a release of current from ionization capacitor CI to intothe primary windings of transformers T710 and T 714. A high voltage isinduced onto the secondary windings of transformers T710 and T714. Thehigh voltage of the transformers creates an ionization path between theelectrodes P1 and electrode N1 to the target. Once the ionization pathis established, the charge from stimulus capacitors CMP and CMNdischarges through the target via the ionization path. The discharge ofcharge from CI, CMP, CMN through the selected electrodes creates currentpulse 1110. After delivery of the current pulse, execution moves toprocess 1112.

After handle 200 provides the pulse of the stimulus signal, processmeasurement 1112 measures the voltage VMH on measurement capacitor CMHat terminal 802. For example, processor 210 measures the voltage acrossmeasurement capacitor CMH. The voltage VMH represents the amount ofcharge delivered by the pulse of the stimulus signal provided in processpulse 1110 for the present environmental conditions. Execution moves toprocess decision 1114.

In process decision 1114, processing circuit 210 determines whether allof the stimulus pulses of the stimulus signal have been provided. TheCEW sends out a predetermined number of current pulses for each stimulussignal. Processing circuit tracks the number of pulse that should besent in a series and the number of pulses that have been sent, so it candetermine whether all of the pulses of a series have been sent. If allof the pulses of a stimulus signal have been provided, execution movesto process end 1124. If all of the pulses of the stimulus signal havenot been provided, execution moves to compare 1116

The pulse provided in process 1116 charges capacitor CMH to voltage VMH.After the pulse has been delivered, process compare 1116 comparesvoltage VMH to the operational target voltage that was determined method1000. The operational target voltage, as discussed above, represents thepredetermined amount of charge or an amount close thereto for thepresent environmental conditions. As discussed above, providing thepredetermined amount of charge or about the same as a predeterminedamount of charge for each pulse may improve the effectiveness of thestimulus signal. If the amount of charge delivered by the pulse is thesame or about the same as the predetermined amount of charge, executionmoves to process discharge 1104.

If the amount of charge delivered by the pulse provided in process 1110is not the same or about the same as the predetermined amount of charge,execution moves to process compare 1122 and subsequent processes 1118and 1120 to adjust the charge delivered by a next pulse of the stimulussignal so that the next pulse provides an amount of charge that iscloser to the predetermined amount of charge.

In process compare 1122, the voltage VMH across measurement capacitorCMH as created by the pulse provided in process pulse 1110 is comparedto the operational target voltage to determine whether the voltage VMHis greater than the operational target voltage. If the voltage VMH isgreater than the operational target voltage, handle 200 determines thatthe previous pulse provided more than the predetermined amount ofcharge, so the amount of charge provided by the next pulse of thestimulus signal should be decreased. If the voltage VMH is not greaterthan the operational target voltage, handle 200 determines that theprevious pulse provided less than the predetermined amount of charge, sothe amount of charge provided by the next pulse of the stimulus signalshould be increased. If the amount of charge for the next pulse of thestimulus signal needs to be increased, execution moves to processincrease 1118; otherwise, execution moves to process decrease 1120.

Handle 200 adjusts the amount of charge delivered by a next pulse of thecurrent by adjusting the amount of charge stored on capacitors CMP andCMN prior to delivering the next pulse. The amount of charge for thenext pulse is adjusted in process increase 1118 and process decrease1120.

In process increase 1118, handle 200 increases the amount of chargestored on capacitors CMP and CMN so that the next pulse of the stimulussignal provides more charge. The amount of charge stored on capacitorsCMP and CMN is increased by charging capacitors CMP and CMN to a highervoltage prior to delivering the pulse. Processing circuit 210 maymaintain a record of the voltages to which capacitors CMP and CMN arecharged for each pulse provided. Processing circuit 210 may use therecord of voltages and the information regarding the amount of chargeprovided by each pulse to determine target voltages, VMPT and VMNT, towhich capacitors CMP and CMN respectively are charged. Executionproceeds to process discharge 1104 where the process of providing thenext pulse of the stimulus signal begins.

In process decrease 1120, handle 200 decreases the amount of chargestored on capacitors CMP and CMN so that the next pulse of the stimulussignal provides less charge. The amount of charge stored on capacitorsCMP and CMN is decreased by charging capacitors CMP and CMN to a lowervoltage prior to delivering the pulse. The record of voltages withrespect to capacitors CMP and CMN discussed above may be used todetermine target voltages VMPT and VMNT. Execution proceeds to processdischarge 1104 where the process of providing the next pulse of thestimulus signal begins.

In process end 1124, the processing circuit 210 end the execution ofmethod 1100.

The foregoing description discusses preferred embodiments of the presentinvention, which may be changed or modified without departing from thescope of the present invention as defined in the claims. Examples listedin parentheses may be used in the alternative or in any practicalcombination. As used in the specification and claims, the words‘comprising’, ‘comprises’, ‘including’, ‘includes’, ‘having’, and ‘has’introduce an open ended statement of component structures and/orfunctions. In the specification and claims, the words ‘a’ and ‘an’ areused as indefinite articles meaning ‘one or more’. When a descriptivephrase includes a series of nouns and/or adjectives, each successiveword is intended to modify the entire combination of words preceding it.For example, a black dog house is intended to mean a house for a blackdog. While for the sake of clarity of description, several specificembodiments of the invention have been described, the scope of theinvention is intended to be measured by the claims as set forth below.In the claims, the term “provided” is used to definitively identify anobject that not a claimed element of the invention but an object thatperforms the function of a workpiece that cooperates with the claimedinvention. For example, in the claim “an apparatus for aiming a providedbarrel, the apparatus comprising: a housing, the barrel positioned inthe housing”, the barrel is not a claimed element of the apparatus, butan object that cooperates with the “housing” of the “apparatus” by beingpositioned in the “housing”. The invention includes any practicalcombination of the structures and methods disclosed. While for the sakeof clarity of description several specifics embodiments of the inventionhave been described, the scope of the invention is intended to bemeasured by the claims as set forth below.

The location indicators “herein”, “hereunder”, “above”, “below”, orother word that refer to a location, whether specific or general, in thespecification shall be construed to refer to any location in thespecification where the location is before or after the locationindicator.

What is claimed is:
 1. A method performed by a handle of a conductedelectrical weapon (“CEW”) for determining whether a pulse of a stimulussignal provided a predetermined amount of charge, the stimulus signalfor impeding locomotion of a human or animal target, the methodcomprising: discharging a capacitance; providing a current for aduration of time to charge the capacitance to a first voltage, theduration of time related to the predetermined amount of charge; aftercharging, recording a magnitude of the first voltage; discharging thecapacitance; providing a pulse of the stimulus signal, providing thepulse charges the capacitance to a second voltage, the second voltage isrelated to an amount of charge provided by the pulse; comparing themagnitude of the first voltage to a magnitude of the second voltage todetermine whether the pulse provided the predetermined amount of charge.2. The method of claim 1 wherein providing the current comprisesmaintaining the current substantially constant over a range oftemperature.
 3. The method of claim 1 further comprising responsive tocomparing, adjusting an amount of charge to be provided by a next pulseof the stimulus signal so that the amount of charge provided by the nextpulse is closer to the predetermined amount of charge.
 4. The method ofclaim 3 further comprising repeating discharging, providing, comparing,and adjusting to provide a further pulse of the stimulus signal.
 5. Themethod of claim 1 wherein discharging comprises discharging thecapacitance until a magnitude of the voltage across the capacitance isabout zero.
 6. The method of claim 1 wherein providing the current for aduration of time comprises: starting a timer to measure the duration oftime; starting provision of the current; determining that the timer hasmeasured the duration of time; and stopping provision of the current. 7.The method of claim 1 wherein comparing comprises determining that whenthe magnitude of the first voltage is greater than the magnitude of thesecond voltage, the amount of charge provided by the pulse is less thanthe predetermined amount of charge.
 8. The method of claim 1 whereincomparing comprises determining that when the magnitude of the firstvoltage is less than the magnitude of the second voltage, the amount ofcharge provided by the pulse is greater than the predetermined amount ofcharge.
 9. A non-transitory computer-readable storage medium encodedwith instructions that, when executed by a processing circuit of ahandle of a conducted electrical weapon (“CEW”), establish a machineperforming a computer-implemented method for determining whether a pulseof a stimulus signal provided a predetermined amount of charge, thestimulus signal for impeding locomotion of a human or animal target, themethod comprising: discharging a capacitance; providing a current for aduration of time to charge the capacitance to a first voltage, theduration of time related to the predetermined amount of charge; aftercharging, recording a magnitude of the first voltage; discharging thecapacitance; providing a pulse of the stimulus signal, providing thepulse charges the capacitance to a second voltage, the second voltage isrelated to an amount of charge provided by the pulse; comparing themagnitude of the first voltage to a magnitude of the second voltage todetermine whether the pulse provided the predetermined amount of charge.10. The method of claim 9 wherein providing the current comprisesmaintaining the current substantially constant over a range oftemperature.
 11. The method of claim 9 further comprising responsive tocomparing, adjusting an amount of charge to be provided by a next pulseof the stimulus signal so that the amount of charge provided by the nextpulse is closer to the predetermined amount of charge.
 12. The method ofclaim 11 further comprising repeating discharging, providing, comparing,and adjusting to provide a further pulse of the stimulus signal.
 13. Themethod of claim 9 wherein discharging comprises discharging thecapacitance until a magnitude of the voltage across the capacitance isabout zero.
 14. The method of claim 9 wherein providing the current fora duration of time comprises: starting a timer to measure the durationof time; starting provision of the current; determining that the timerhas measured the duration of time; and stopping provision of thecurrent.
 15. The method of claim 9 wherein comparing comprisesdetermining that when the magnitude of the first voltage is greater thanthe magnitude of the second voltage, the amount of charge provided bythe pulse is less than the predetermined amount of charge.
 16. Themethod of claim 9 wherein comparing comprises determining that when themagnitude of the first voltage is less than the magnitude of the secondvoltage, the amount of charge provided by the pulse is greater than thepredetermined amount of charge.
 17. A handle of a conducted electricalweapon (“CEW”) for determining whether a pulse of a stimulus signalprovided a predetermined amount of charge, the stimulus signal forimpeding locomotion of a human or animal target, the handle comprising:a processing circuit; a memory; a capacitance; a current source; atimer; a signal generator that provides the stimulus signal; wherein:the processing circuit discharges the capacitance; the current sourceprovides a current for a duration of time to charge the capacitance to afirst voltage, the duration of time measured by the timer, the durationof time related to the predetermined amount of charge; the processingcircuit records in the memory a magnitude of the first voltage; theprocessing circuit discharges the capacitance; the signal generatorprovides a pulse of the stimulus signal, providing the pulse charges thecapacitance to a second voltage, the second voltage is related to anamount of charge provided by the pulse; the processing circuit comparesthe magnitude of the first voltage to a magnitude of the second voltageto determine whether the pulse provided the predetermined amount ofcharge.
 18. The handle of claim 17 further comprising a switch, whereinthe processing circuit closes the switch to discharge the capacitanceuntil a magnitude of a voltage across the capacitance is about zero. 19.The handle of claim 17 wherein for the current source to provide thecurrent for the duration of time, the processing circuit: initializesthe timer; starts the timer counting; instructs the current source toprovide the current; detects the timer has counted the duration of time;and instructs the current source to stop providing the current.
 20. Thehandle of claim 17 wherein the current is substantially constant over arange of temperature.
 21. The handle of claim 17 wherein the processingcircuit determines that when the magnitude of the first voltage isgreater than the magnitude of the second voltage, the amount of chargeprovided by the pulse is less than the predetermined amount of charge.22. The handle of claim 17 wherein the processing circuit determinesthat when the magnitude of the first voltage is less than the magnitudeof the second voltage, the amount of charge provided by the pulse isgreater than the predetermined amount of charge.